Commit 275060c4 authored by Hangyu Hua's avatar Hangyu Hua Committed by Zhengchao Shao
Browse files

net: sched: sch_multiq: fix possible OOB write in multiq_tune() 

mainline inclusion
from mainline-v6.10-rc3
commit affc18fdc694190ca7575b9a86632a73b9fe043d
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6R4J
CVE: CVE-2024-36978

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=affc18fdc694190ca7575b9a86632a73b9fe043d



--------------------------------

q->bands will be assigned to qopt->bands to execute subsequent code logic
after kmalloc. So the old q->bands should not be used in kmalloc.
Otherwise, an out-of-bounds write will occur.

Fixes: c2999f7f ("net: sched: multiq: don't call qdisc_put() while holding tree lock")
Signed-off-by: default avatarHangyu Hua <hbh25y@gmail.com>
Acked-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarZhengchao Shao <shaozhengchao@huawei.com>
parent dbd6a8b1

net/sched/sch_multiq.c

+1 −1
Original line number Diff line number Diff line
@@ -185,7 +185,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt, 


	qopt->bands = qdisc_dev(sch)->real_num_tx_queues;



	removed = kmalloc(sizeof(*removed) * (q->max_bands - q->bands),

	removed = kmalloc(sizeof(*removed) * (q->max_bands - qopt->bands),

			  GFP_KERNEL);

	if (!removed)

		return -ENOMEM;